Field of the Invention
The present invention relates to a hearing aid that corrects hearing difficulties caused mainly by aging.
Description of the Related Art
Most of hearing aids known in the art are equipped with a sound amplifier. Such a conventional hearing aid amplifies unnecessary noises together with sounds to hear, posing a problem that the user has difficulty in accurately obtaining essential information during conversations.
Under such circumstances, Japanese Unexamined Patent Application Publication No. 2002-517279 (patent document 1) has proposed a hearing aid requiring no power supply. Patent document 1 has disclosed an earplug that is composed of a first element and a second element, each element having an opening, and that applies an equal pressure to the interior and exterior of the external ear. Patent document 1 states that the earplug allows the user to have a conversation from which noises and unpleasant sounds are cut off.
As described above, the conventional hearing aid poses a problem that it amplifies unnecessary noises to make it difficult for the user, in some cases, to have a smooth conversation.
The earplug described in patent document 1 poses a problem that when the earplug is used, it blocks up most of the external ear and consequently reduces incoming sounds other than noises.
The present invention has been conceived in order to solve the above problems. An object of the present invention is to provide a novel hearing aid that allows the user to clearly hear necessary sounds while cutting off noises.